Doesn't the BBC go by surveys of holders of "TV licenses" or something rather than ratings?

So if one person watches 10 shows, and another only watches 1, they both only get a vote to keep X shows.

So as long as there are enough holders who care more about nonsense than quality entertainment, the show will continue.

Of course, (I just looked it up, may not have tried hard enough) the surveys appear to be unreleased and anonymous, so the higher ups can more or less make it up.